1. Field of the Invention
This invention relates the medical arts and more particularly to a flexible protective sheath for subcutaneous insertion into a body such as for facilitating urological, and gastrological procedures.
2. Description of the Related Art
The invention can be used in a variety of surgical fields such as urology and gastroenterology. The invention will be described by way of example in connection with the field of urology. One of the most common urological procedures, both historically and in current practice, is the placement of a catheter in the urethra for the purpose of draining urine or fluid, to diagnose problems or to maintain anatomic continuity. This procedure is performed by inserting the catheter manually while noting any resistance to forward movement as shown by a failure of the catheter to slide smoothly into the urethra. While most placements proceed without problems, typically about ten percent of urinary catheter placements are difficult, causing a substantial burden on the delivery of effective care through the healthcare system. The most common problem is tetany, a spasm of the external urinary sphincter or stricture of the urethra. Stones, and even clots descending from the bladder, also constitute urethral obstructions. In addition, urethral lumen calibers vary considerably, and particularly with urethritis, BPH, urethritis stricture disease and prostate disorders in males. The cost to the healthcare system, hospitals, clinics and doctors' offices is substantial. In addition, the delay in servicing urological catheter patients in a timely manner constitutes poor medical efficiency, delivery and control. When difficulty is encountered, the resulting frustration among healthcare professionals, especially nurses, physician extenders and physician assistants, creates a very real feeling of ineffectiveness on the part of these healthcare workers, to say nothing of the dissatisfaction on the part of the patients caused by the delay and added discomfort. While the dollar cost to the healthcare system is not the only concern, such elements as added labor and material costs, time delays for patient rectification, excess space and equipment required, catheter kit value, nurse technician and physician costs constitute an expense to the healthcare system of surprising proportions. The best available current data indicates about 150,000 urinary catheter placements are made in the United States per day. Of these, about 15,000 are difficult. From this data it can be calculated that the cost to the healthcare system for additional services by healthcare professionals in the United States is over $700 million dollars per year. Moreover, the additional space and equipment amounts to at least $800 million per year for a total added cost of about $1.5 billion per year.
Accordingly, an important object of the present invention is to virtually eliminate these additional costs, greatly improve patient comfort and satisfaction, as well as shortening the time required for catheter placement while adding only a relatively small cost to the equipment required.
Another more specific object of the invention is to eliminate or drastically reduce problems associated with difficult catheter passage through the urethral or other body opening including the following problems among others: the formation of iatrogenic trauma strictures, urethral bleeding, urethral mucosal lining tears, patient pain or discomfort, scar tissue formation, treatment delay, increased infection potential, and inappropriate use of antibiotic which may enhance a recalcitrant immune strain modification of the offending organism.
A further specific object of the invention is to provide an apparatus and method for safely passing a flexible sheath through the urethra of both male and female human patients with a provision for enabling healthcare workers such as nurses and physician's assistants who are not board certified urologists to negotiate most obstructions in a safe, efficient and timely manner without the need of a cystoscope.
In several kinds of surgical operations, e.g., urological procedures, it is the current practice to insert and remove various instruments through the urethra several times during a single surgical operation. The repeated insertion and removal of instruments often requires a significant amount of force. This can of course traumatize the tissue. It is therefore another object of the present invention to eliminate the need for inserting and removing a series of surgical instruments by passing them through an opening in the body in a manner that can cause discomfort or injure the tissue and in that way reduce the possibility of bleeding, trauma, inflammation; infection, false passage, and long-term complications such as scarring.
In addition, the manipulation of a surgical instrument or other object that is partially or completely inserted into the body can also result in damage to the surrounding tissue. A more specific object of the invention is to minimize the possibility of damaging the tissue through either the manipulation or the repeated insertion and removal of instruments that have to be used in succession to complete a surgical operation: For example, in many urologic procedures a cystoscope is inserted blindly or under direct vision for evaluation and diagnosis. The cystoscope is frequently removed and another instrument then inserted for lavage, cauterization, extraction or surgery. A series of such instruments are usually inserted in a logical sequence. Finally, at the conclusion of the endoscopic or percutaneous procedure, it is frequently necessary to insert a rubber tube or sheath as a percutaneous drain or for drainage of the bladder or as a post-op drain. The insertion and removal of each of these other instruments increases the chances for traumatizing or injuring surrounding tissue or even creating a false passage and losing access. As already noted the inventions have applications in a variety of surgical specialties. Each time a body orifice, e.g. oral cavity, urinary, gastrointestinal tract, or other opening is manipulated, the potential for bacteremia is increased. In short, tissue trauma can result from retrograde or antegrade passage instrumentation or removal of foreign bodies. many endoscopic, percutaneous or laparoscopic instruments have a relatively small diameter working channel which limits the size of biopsy specimens. The small size limits the removal of such specimens or foreign bodies by necessitating multiple insertions and withdrawals. This prolongs the operation and is an additional source of tissue trauma.
Flexible catheters have been previously proposed to guide surgical tools as they are inserted into the body of a patient during the course of a surgical procedure. These tools are inserted and removed during a procedure with the object of the catheter being to protect the body from damage and to guide the surgical tools to the desired position. Catheters, now in common use, however have thick walls, typically about 2 mm or more in thickness, which have limited capacity to expand so that some instruments can be passed through the lumen of the catheter only with great difficulty or not at all.
Percutaneous Systems Inc. has proposed the use of a thin walled tube for urethral intubation in U.S. patent application publication 2005/0197627 published Sep. 8, 2005. However there is no way to hold the sheath in place one inserted. Moreover, the sheath has no balloon or passage for introducing an inflation fluid to a balloon. In addition, the sheath is closed at its distal end so that it can be pushed through the urethra.
A thin walled flexible and flaccid sheath is preferable for insertion into the body and to act as a guide as it takes less room than a standard catheter, is not as stiff as a catheter and is expandable and contractible for facilitating instrument insertion and withdrawal. However the insertion and positioning of a thin sheath has been difficult to accommodate largely because of the thin flexible, flaccid walls.
Accordingly the need exists for a sheath which can be easily installed and remain in place during a procedure and works well in conjunction with tools for placing the sheath in the body.
These and other more detailed and specific objects of the present invention will be better understood by reference to the following figures and detailed description which illustrate by way of example of but a few of the various forms of the invention within the scope of the appended claims.